Process of obtaining absolute alcohol



June I 1926.

J. A. STEFFENS PROCESS OF OBTAINING ABSOLUTE ALCOHOL Filed April 5, 1921 4am lift Patented 1, 1926.

UNITEDI' STATES PATENT .orr ca.

JOHN A. STEPHENS, OI BALTIMORE, MARYLAND, ASSIGNOR TO U. S. INDUSTRIAL,

ALCOHOL (10., A CORPORATION OF WES'l VIRGINIA.

PROCESS OI OBTAINING ABSOLUTE ALCOHOL.

Application fled Allrtl 5, 1921. Serial 170. 458,888.

My invention relates particularly to a process designed to obtain alcohols having a high strength by removing water from the same but it has especial reference to the production of absolute alcohol.

The object of my invention is to provide a process whereby alcohols may be separated from water and especially by means of which absolute alcohol may be obtained in accordance with a commercially practicable system.

More particularly, the object of my invention is to provide a process based upon the utilization ofa third liquid which is miscible with the alcohol but substantially immiscible with water and which is of such a character that when the three constituents are present vapors of the same are evolved by distillation containing a considerable percentage of water and the third liquid so that all the water and the third.liquid may be removed in this way from the residual constituent, which is the alcohol. The evolved vapors are comprised of a ternary mixture of the three constituents. This third liquid may be of any one of a number of different compounds, such, for example, as benzol, carbon tetrachloride, hexane, etc., but I prefer to use benzol. a

One of the objects of my invention is to avoid the necessity of using a large amount of benzol in carrying out the process. I A further ob'ect is to so-'arranged"the process as-to eua Is a close regulation thereof tobe obtained, inasmuch as in my proccss the dehydration of the alcohol is carried out in a column, the upper portionof which is fed continually with a quantity of the condensate of fixed composition passing out of the top of the tower, as a condensate rich in water is obtained with a comparatively small load being placed upon thitauxiliary apparatus and as the alcohol evolved in the form of vapor is returned to the lower continually in the form of a liquid having a fixed composition obtained by a uniform rectification of the recovered a'lcohol.

' A further object is to so arrange the sys-' tem as to enable the several 0 rations to .be e ned out c inuo y, 80 that the several operations ma be carried out largely independently of t 1e remaining 0 -erations thus enablingthe operator of tie system to recover in case at any time any one of the o erations does not function. This is broug t about especiall by reason of the complete removal ofthe nzol from the distillate prior to the rectification of the dilute alcohol. By reason of these features in my process the system may be operated continuously.

Further objects will appear from the detailed description thereof contained hereinafter. I

While my invention is capable of embodiment in many difl'erent forms, for the purpose of illustration I shall describe only certain ways in which my invention may be carried out, and while my invention is capable of being carried out in connection with many diflerent ty es of ap aratus, I have shown only one 531111 of tiie same in the accompanying drawings, in which- 7 The figure is a diagrammatic representation of an apparatus which may be used in connection with my invention.

In the drawings, I have shown a valved inlet pipe 1 for feeding continuously into the apparatus an alcohol mixed with water, and which, by way of example, may feed to the system ethyl alcohol having a strength of 95%. Leading into the pipe 1 there is a the system additional amounts of benzo to replace the small quantities thereof which are lost by evaporation therefrom. The alcohol and benzol are fed to the system in proportions such that in the circulating'systern, at any given time, there would be approximately equal parts by weight of 95% alcohol and benzol but preferably a slightly smaller uantity of the benzol than of the 95% alco o]. The valved pipe 1 leads into a tail-box 3 which is connected by a liquid sealed. pipe 4 to a dehydrating column 5 which Is constructed in any suitable manner but which ma have, for example, a plurality of plates t e same as in the case of the usual alcohol rectifying column. The column 5 has at the bottom an inlet 6 and.

an outlet 6" for steam for heating the column weight of benzol, 7.4% by weight of water, and 18.5% b weight of alcohol and absolute alcohol ows from the liquid sealed outlet pipe 7. The evolved vapors pass out by means of a pipe 8 into a dephlegmator 9 which is connected b a liquid sealed pi e 10 to the top plate 0 the column. The ephlegmator is cooled in the usual way with the aid of water inlet and outlet ipes 11 and 12. The uncondensed vapors rom the dephlegmator 9 pass into a condenser 13 through a pipe 13 the temperature in which is at approximately 649 0., said condenser being cooled by water passing through inlet and outlet pipes 14 and 15 and the condemsate therefrom enters a vented sight-glass 16 from which a portion of -the condensate passes through a valved pipe 17 to the pipe 10 and'thence to the top of the column 5. The main portion .of the condensate is conducted by a pipe 18 to a tail box 19 and thence by :1 pi e 20 to a separating chamber 21. The liquid received in the separating chamber immediately separates into two liquid phases forming la ers, the upper la er of which is rich in benzo but poor in alco o1 and water, while the lower layer is rich in alcohol and water but poor in henzol. The composition of the respective layers is approximately as follows: The upper layer contains approximately 85.6% by weight of benzol, 2.8% by weight of water, and 11.6% by weight of alcohol, while the lower layer contains approximately 8.1% by weight of benzol, 40.6% by weight of water, and 51.3% by weight of alcohol. The upper layer is conveyed b a vented pipe 22 having a liquid seal 23 ack to the tower 5 while the lower layer passes b as vented pipe 24 to a scrubber 25., In or er to remove the remainder of the bcnzol, water is introduced into the scrubber 25 by :1 pi e 26 thus producing therein two layers of liquid, the up r layer of which contains the remainder o the henzol. The benzol layer is conducted from the scrubber b a vented ipe 27 to the liquid seal 23 an thence to t e tower 5, while the lower layer is conveyed through a vented liquid sealed pipe 28 to an alcohol rectifying column 29 having a steam inlet pipe 30 and an outlet 30 in the usual way for indirect heating and a liquid scaled drawofl' pipe 31 for water at the bottom of the column. The lower portion of the column 29 is maintained at a temperature just above 100 C. The evolved alcohol vapors containing' some water pass out of the top of the column through a pipe 32 to a dephlegmator 33 constructed substantially the sam as the dephleginator 9 and which is ar ranged to return the condensate therein to the top of the column 29 by a liquid sealed pipe 34. The vapors from the dephlegmator 33 pass through a pipe 35, the vapors in which are at a temperature of approxi eeann mately 76 (3., to a condenser 36 constructed the same as the condenser 13. The condensate from the condenser 36, which comprises approximately 95% alcohol enters a vented sig it-glass 37 and a portion of the same asses back through a valved pipe 38 to the iquid sealed pipe 34 and thence to the top of the column 29. while the remainder thereof enters a tail-box 39 and is conveyed therefrom by a valved pipe 40 direct to the liquid sealed pipe 23 and thence to the column 5. The apparatus is also arran ed in an efl'ective manner in that the portions thereof rcquiring observation are located upon an operating floor 41.

In carrying out my invention. the alcohol containing water and the benzol is fed into the column 5 the lower portion of which is maintained at a temperature slightly below 784 C. The vapors of alcohol, water and benzol will be distilled from the top of the column 5 thus leaving behind absolute alcohol which passes out of the bottom of the column through the pipe 7. The evolved vapors pass into t 1e dephlegmator 9, whence some of the condensate is returned to the topmost plate in the column 5 and at the same time a small portion of the condensatc from the condenser 13 is also conveyed into the tower at the same int, thus scaling the uppermost plates in t e column with a liquid of a constant composition and which is very close to the com osition of the evolved vapors. This not on y provides uniform conditions at the top of the tower but enables the process to be conducted with a comparatively small quantity of benzol so that the condensate reaching the separating chamber 21 will be rich in the water to be removed. \Vhen the liquid condensate reaches the separating chamber 21 it immediately divides into two layers, the up er layer, comprised principally of benzol, cing conveyed back to the tower 5, while the lower layer, comprised principally of alcohol and water but containing some benzol, is conducted to the scrubber 25 where water is added in the proportions of approximately one part by weight of water to one part by weig it of the incoming liquid. This se arates out the benzol into an upper layer which is conveyed back to the column 5. while the dilute alcohol is conducted to the alcohol rectifying column 29. This column is required merely to rectify the alcohol, said column at its lower portion being maintained at a temperature of a proximately 100 C., the water from whici passes out from the bottom of the column, while the alcohol substantially in strength is collected as a condensate having a lixed composition and temperature which is returned to the column 5. Inasmuch as the alcohol returned to the column 5 has a definite composition and temperature, and as the benzol has been substantially entirely removed the separating) the therefrom, the conditions in the upper portion of the column 5 are comparatively uniform so far as the character of the incoming alcohol is concerned. Furthermore, inns much as the hull: of the bensol is returned chamber 21 to 5, while the scru hing is applied only to the small ortiun of the henzol recovered in the-scru her 25, the beam] is returned to the column 5 in a drier form than would otherwise be the case and this also con'duces to uniformity in the operation of process. or the same reason less water is carried back into the column 5 and there is consequently a more cii'ective separation of the echo! from the water. By roviding a system of this character in which the several parts of the system operatewithout s degree of dependence upon one anot or it is possible to conduct the recess with t uniformity of results and in such a way that the failure of any rtion of the system to function temporal-i 31 would not interfere with the efl'ective operation of the" em as a whole. For these reasons, furermore, it is practicable to obtain absolute alcohol with the process continuously.

While I have described my invention above in detail I Wish it to beunderstood that man changes may be made therein without eparting from the spirit of the same.

I claim:

1. The process of obtaining absolute alcohol which comprises distilling in a column a mixture of an alcohol, water and a third liquid miscible with the alcohol but substantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column, condensin a art of the evolved vapors and returning it to the top of the column, and se aratin the constituents of the remainder o the said vapors.

2. The process of obtaining absolute alcohol which comprises distilling in a. column a mixture of an alcohol, water, and a third liquid miscible with the alcohol but substantially immiscible with water to form a constant boilin mixture and to obtain absolute alcohol at t e bottom of said column, condonning a part of the evolved vapors and returning it to the top of the column, condensing a further quantity of the vapors and also returning it to the top of the colum, and se uniting the consti uents of the remainder o the and vs rs.

8. The process of obtaining absolute alcohol which comprises distilling alcohol, water and a third li uid miscible with the alcoho but subetantifiimmiscible with the water, to form a 00 nt boiling mixture and to obtain absolute alcohol; condensing a portion'of the evolved vapors and returning it e vapors substantially gmthe liquid being digtillheed; con sing a su nent portion'o vapors andre itinparttothesaidliquid mixture distilled and washingthe rewater to separate out saidalcohol, water, a

liquid to the liquid mixture being distilled. I

and treatin the other layer to remove substantially e remainder of said third liquid,

and distilling the remainder of said layer to form high str alcohol, 'and returning the latter to t e liquid mixture being distilled.

5. The process of obtaining absolute alcohol which comprises distilling alcohol, water and a third li uid miscible with the alcoho but substantial immiscible with theiwater, toformaeo tboiling mixture andto obtain absolute alcohol; condensing a portion of the evolved vapors and returning it to the liquid mixture being distilled to provide'a reflux; condensing a. subsequent portion of the vapors and allowing the condeneate to separate into two luyersil ing the la er richer in said third uid to the liqui mixture being distill and treatin the other layer to remove substantially t e remainder of said third liquid,

distilling the remainder of said is or to largely separate aqueous alcohol 0. hi h strength from the water, and returning 1: e alcohol to the liquid mixture being distilled.

B. The process of obtaining absolute alcohol, which comprises distillin a mixture of an alcohol, water, and a thir liquid miscible with the alcohol but substantial] immiscible with water, to form a constan boiling mixture and to obtain absolute alcohol; condensing a portion of the evolved vapors, washing it with water by successive washings to separate the third It old, and returning the latter to the liqm mixture bein distilled.

The process which comprises distillin a mixture of an alcohol, water and s thir liquid, miscible with the alcohol but sub stantially immiscible with water, and se rating out from the condensed evolved by allowing the condensate to separate 1%:

two liquid layers, w with Wt layer contaimn the am er proportion of the third liqui and the third liquid to the liquid mixture "n3 distilled. 8. The process of obtaining abeolutealcoreturnall of the third liquid by allowing hol which comprises distilling alcohol, water and a third li uid miscible with the alcobo but subsfantiu y immiscible with the water, to form a constant boiling mixture and to obtain absolute alcohol; condensilzf the distillate and allowing a portion lei-e0! to as units into two laiers, returnin the layer ri er in said third quid to the i uid mixture being distilled, treatin the ot \er layer to se arate subetantiall tie remainder of said ird liquid from ie water and alcohol therein and return this remainder also to the li uid mixture being distilled.

9. e process which comprises distillin a mixture of an alcohol, water and'u booze and separating out from the condensed evolved vapors substantially all of the benzol the condensate to separate into two liquid layers, washi with water the layer contaimn the smal er pro ortion of the booze] an that: returni r t benml to the liquid mixture being dis 'illed.

10. The process of obtaining absolute alco- "hol which comprises distilling alcohol, water,

and a third hquid miscible with the alcohol but substantially immiscible with the water, to form a constant boiling mixture and to obtain absolute alcohol; condensing the evolved vapors and allowing a portion thereof to'separate into two layers, returning the layer richer in said tlnrd liquid to the liquid mixture being distilled, an treatin the other layer to remove therefrom alcoho of approximately 0 concentration and returning it in li uid orm to the liquid mixture being distill 11. The process which comprises distilli a mixture of alcohol, water and a bani; and se arating out from the condcn evolve vapors substantially all of the benzol by allowin the condensate to separate into two liqui layers washing with water the layercontninin t is smaller proportion of the bcnzol and t 1011 irturniu lhv bcuzol to the liquid mixture bcinig disti led, thcirhy obtaining absolute alcoho 12. The process of obtaining absolute alcohol which comprises distillin an alcohol, water, and a tlurd liquid misc ble with the alcohol but substantially immiscible with the water, to form a constant boilin r mixture and to obtain absolute alcoho condensin the constant boiling mixture and separa an out from a portion thereof the third liquid, distilling the remainder of said portion of the condensate to obtain a more concentrated alcohol, and returning the lutter in ii uid form to ing disti' led.

13. The process of obtaining absolute alcohol which comprises distilling in a column an alcohol, water and a third "quid miscible with the alcohol but substantially immiscible with the water, to form a constant boiling mixture and to obtain absolute alcohol; conthe liquid mixture bcdensing the distillate and allowing a portion thereof to flow back as reflux, allowing the remainder of the condensed distillate separate into two layers, returning the layer richer in said third liquid to the upper art of said oohunn below the point of mtr notwo of said influx but relatively near it.

14. The process of obtaining absolute alcohol which comprises continuously distilling a mixtuie of an alcohol, water and a thi liquid, miscible with the alcohol but substantiallyinuniscihle with the water, to form a constant boiling mixture and to obtain absolute alcohol; condensing the evolved vapors and se arating a portion thereof so as to remove t erefrom substantiall all of the third l quid, returning the this li old to the liquid mixture being distilled, istilling the residue of the said portion of the condensate to obtain therefrom an aqueous alcohol of high strength andrcturning the same to the liquid mixture being distilled.

15. The process of obtaining absolute alcohol which comprises continuously distilling in a column a mixture of an alcohol, water, and a third li uid miscible with the alcohol but substantia ly immiscible with the water, to form a constant boilin mixture and to obtain absolute alcohol at e bottom of said column, separating the condensate from the evolved vapors into a major portion and a minor portion, treatm said major portion so as to remove there rom suhstantinlly all of the third liquid, returnin the latter to the column, distil ing the reel us of the major portion to obtain therefrom an aqueous uh-ool of high strength and returning the some to the first-mentioned liquid mixture being distilled, the minor ortion of the condensate being returned to t to top of the aforesaid column.

16. The process of obtaining absolute alcohol which comprises continuously distillin v in a column an alcohol, water and a bcnznl; continuously separating the bulk of the condensate obtained from the evolved vapors so as to remove therefrom substantially all of the benzol, returning the bcnzol to the column, distilling the residue of said bulk of the condensate to obtain therefrom an aqueous alcohol of high strength and returnin the same mixture being distilled, the unseparated portion of the condensate being returned to the top of the first mentioned column.

17. The process of obtaining absolute alco hol which compriscs continuously distilling in a column alcohol. water (and a benzol, continuously separating the bulk of the coudeusate obtained from the evolved vapors s0 us to remove therefrom substantially all of the bcnzol, returning the benzol to the column, distilling the residue of said bulk of the condensate to obtain therefrom an aqueous alcohol of high strength and return to the first mentioned liquid ing the same to the first mentioned column, the unseparated portion of the condensate being returned to the top of the first mentioned column. a q

18. The process of obtaining absolute alcohol which comprises continuously distilling an alcohol, water, and athird liquid miscible with the alcoholbut substantially immiscible with the water, to form a constant boiling mixture and to obtain absolute alcohol; separating a portion of the condensate obtained from the evolved va ors so as to remove therefrom substantially all of the third liquid, returnin the latter to the liquid mixture being disti led, distilling the residue of said portion of the condensate to obtain therefrom a more concentrated alcohol, and returnin the same to the first-mentioned liquid mixture being distilled.

19. The process of obtaining absolute alcohol which comprises distillin an alcohol, water, and a third liquid whici is miscible with the alcohol but substantial] immiscible with water, to form aconstant oiling mixture and to obtain absolute alcohol; condensing a portion of the evolved vapors and separating therefrom an aqueous alcohol su stantially free from the third liquid, rectifyin it so as to obtain an a ueous alcohol of hig or strength and returning the latter in li uid form to the liquid mixture being distil ed.

20. The process of obtaining absolute a1- cohol which comprises distilling in a column an alcohol, water, and a third li uid which is miscible with the alcohol but an stantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing a portion of the evolved vapors and separating therefrom an aqueous alcohol substantially free from the third liquid rectifying it so as to obtain an aqueous alcohol of higher strength, and returning the latter in liquid form to the top of the column.

21. The 1process of obtaining obsolute alcohol whic comprises distillin in a column an alcohol, water, and a third liquid that is miscible with the alcohol but substantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing the vapors evolved and returning part thereof to the top of the column, separating from the remainin condensate an aqueous alcohol substantial y free from the third liquid; rectifying it so as to obtain an aqueous alcohol of higher strength, and returning the latter to the column below the point of introduction of the aforesaid condensed vapors.

22. The process of obtaining absolute alcohol which comprises distillin in a column an alcohol, water, and a third liquid that is miscible with the alcohol but substantially xi mmiscible with water,to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing the vapors evolved and returning part thereof to the top of the column; separating from the remainin condensate an aqueous alcohol substantial y free from the third liquid; rectifying it so as to obtain an aqueous alcohol of higher strength, and returning the latter in li uid form to the column below the point of introduction of the aforesaid condensed vapors.

23. The process of manufacturing substantially anhydrous alcohol which comprises distilling an alcohol, water, and a third liquid that is miscible with the alcohol but substantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol; separating from the portion of the vapors evolved the third liquid and an a ueous alcohol substantiall free from the third liquid; rectifying saic aqueous alcohol so as to obtain an aqueous alcohol of higher strength, and returning the latter in li uid form to the liquid mixture bein distil ed; and also returning the said third litpiid to the liquid mixture being distilled.

n testimony that I claim the foregoing, I

have hereunto set my hand this 26th day of January, 1921.

JOHN A. STEFFENS.

ing the same to the first mentioned column, the unseparated portion of the condensate being returned to the top of the first mentioned column.

18. The process of obtaining absolute alcohol which comprises continuously distilling an alcohol, water, and athird liquid miscible with the alcohol but substantially immiscible with the water, to form a constant boiling mixture and to obtain absolute alcohol; separating a portion of the condensate obtained from the evolved va ors so as to remove therefrom substantia 1y all of the third liquid, returning the latter to the liquid mixture being disti led, distilling the residue of said portion of the condensate to obtain therefrom a more concentrated alcohol, and returnin the same to the first-mentioned liquid mixture being distilled.

19. The rocess of obtaining absolute alcohol whic' comprises distilling an alcohol, water, and a third liquid which is miscible with the alcohol but substantial] immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol; condensing a portion of the evolved vapors and separating therefrom an aqueous alcohol su stantially free from the third liquid, rectifyin it so as to obtain an aqueous alcohol of big er strength and returning the latter in liquid form to the liquid mixture being distil ed.

20. The process of obtaining absolute alcohol which comprises distilling in a column an alcohol, water, and a third li uid which is miscible with the alcohol but an stantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing a portion of the evolved vapors and separating therefrom an aqueous alcohol substantially free from the third liquid, rectifying it so as to obtain an aqueous alcohol of higher strength, and returning the latter in liquid form to the top of the column.

21. The 1process of obtaining obsolute alcohol whic comprises distillin in a column an alcohol, water, and a third liquid that is miscible with the alcohol but substantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing the vapors evolved and returning part thereof to the top of the column, separating from the remainin condensate an aqueous alcohol substantial y free from the third liquid; rectifying it so as to obtain an aqueous alcohol of higher strength, and returning the latter to the column below the point of introduction of the aforesaid condensed vapors.

22. The process of obtaining absolute alcohol which comprises distillin in a column an alcohol, water, and a third iquid that is miscible with the alcohol but substantially immiscible with water,to form a constant boiling mixture and to obtain absolute alcohol at the bottom of said column; condensing the vapors evolved and returning part thereof to the top of the column; separating from the remainin condensate an aqueous alcohol substantial y free from the third liquid; rectifyin it so as to obtain an aqueous alcohol of hig er strength, and returning the latter in li uid form to the column below the point 0 introduction of the aforesaid condensed vapors.

23. The process of manufacturing substantially anhydrous alcohol which comprises distilling an alcohol, water, and a third liquid that is miscible with the alcohol but substantially immiscible with water, to form a constant boiling mixture and to obtain absolute alcohol; separating from the portion of the vapors evolved the third liquid and an a ueous alcohol substantially free from the tird liquid; rectifying said aqueous alcohol so as to obtain an aqueous alcohol of higher strength, and returning the latter in li uid form to the liquid mixture bein distil ed; and also returning the said thir llqilld to the liquid mixture being distilled.

. n testimony that I claim the foregoing, I have hereunto set my hand this 26th day of January, 1921.

JOHN A. STEFFENS.

Certificate of Correction.

It is hereb certified that in Letters Patent No. 1,586,717,

the a p cation of John A. Stefl'ens, of Baltimore, Mary and, .;for an improveof Obtaining Absolute Alcohol, errors appear requiring correction as follows: Page 4, line 69, c

insert the word to, and same line after the word into str1ke out and that the said letters Patent should be read-"with these corrections conform to the record of tbe'case in the Patent Oflice. Signed and sealed this 29th day of June, A. D. 1926. 4 7

upon mant in specification word separate the word two therein that the same may nted June 1, 1926,

in the printed aim 13, before the M. J. Moons, I Comm-of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,586,717, nted June 1, 1926, upon the a plication of John A. Stefl'ens, of Baltimore, Mary and, .for an improvement in recesses of Obtaining Absolute Alcohol, errors up 7 in the printed specification requiring correction as follows: Page 4, line 69, c 13, before the word separate insert the word to, and same line after the word into strike out the word two; and that the said Letters Patent should be read-with these corrections therein that the same may conform to the record of themes in the Patent Ofiice.

Signed and aeeled this 29th day of June, A. D. 1926.

[mm] M. J. MOORE,

Acting 'b'onmtiuionaiof Paton. 

